This view of the twilight sky and Martian horizon taken by NASA's Curiosity Mars rover includes Earth as the brightest point of light in the night sky. Earth is a little left of center in the image, and our moon is just below Earth.

This frame from an animation from NASA's Mars rover Curiosity shows the rover drilling into rock target 'Cumberland.' The drilling was performed during the 279th Martian day, or sol, of the Curiosity's work on Mars (May 19, 2013).

This image from the Mars Hand Lens Imager on NASA's Mars rover Curiosity shows the patch of rock cleaned by the first use of the rover's Dust Removal Tool (DRT). The tool is a motorized, wire-bristle brush on the turret at the end of the rover's arm.

The two bodies in this portion of an evening-sky view by NASA's Mars rover Curiosity are Earth and Earth's moon. The rover's Mast Camera (Mastcam) imaged them in the twilight sky of Curiosity's 529th Martian day, or sol (Jan. 31, 2014).

This is a map of lower Mount Sharp on Mars, showing the major geologic units identified from orbit. The rocks of the 'Murray Formation,' mapped in green, likely represent the oldest layers of Mount Sharp that NASA's Curiosity rover will explore.

Data from the Alpha Particle X-ray Spectrometer (APXS) instrument on NASA's Mars rover Curiosity show an unusual enrichment of silicon in the rocks dubbed 'Wildrose' and 'Bonanza King,' relative to other rocks studied at Gale Crater on Mars.

The 'Bonanza King' rock on Mars, pictured here, was tapped by the drill belonging to NASA's Mars rover Curiosity. The tapping resulted in sand piling up on the rock after drilling, showing the rock was not firmly in place.

The route of NASA's Mars Curiosity rover up the slopes of Mount Sharp on Mars is indicated in yellow in this image. The rover's current position is marked with a star. This new route provides excellent access to many features in the 'Murray Formation.'

This topography map shows a portion of the Gale Crater region on Mars, where NASA's Mars Curiosity rover landed on August 6, 2014. The rover (marked with a star) is currently headed toward 'Pahrump Hills.'

This image from the front Hazcam on NASA's Curiosity Mars rover shows the rover's drill in place during a test of whether the rock beneath it, 'Bonanza King,' would be an acceptable target for drilling to collect a sample.

This Aug. 12, 2012, image from the Mastcam on NASA's Curiosity Mars rover shows an outcrop that includes the 'Bonanza King' rock under consideration as a drilling target. Raised ridges on the flat rocks are visible at right.

This image, taken on Aug. 4, 2014, from the Navigation Camera on NASA's Curiosity Mars rover shows wheel tracks printed by the rover as it drove on the sandy floor of a lowland called 'Hidden Valley' on the route toward Mount Sharp.

The main map shows landforms near NASA's Curiosity Mars rover as the rover's second anniversary of landing on Mars nears. The gold traverse line ends at Curiosity's position as of July 31, 2014 (Sol 705).

NASA's Curiosity Mars rover used the Mars Hand Lens Imager (MAHLI) camera on its arm to catch the first images of sparks produced by the rover's laser being shot at a rock on Mars. The left image is from before the laser zapped this rock, called 'Nova'.

A Martian target rock called 'Nova,' shown here, displayed an increasing concentration of aluminum as a series of laser shots from NASA's Curiosity Mars rover penetrated through dust on the rock's surface.

This rock encountered by NASA's Curiosity Mars rover is an iron meteorite called 'Lebanon,' similar in shape and luster to iron meteorites found on Mars by the previous generation of rovers, Spirit and Opportunity.

This map shows in red the route driven by NASA's Curiosity Mars rover from its landing site at 'Bradbury Landing.' The white line shows the planned route to reach destinations on Mount Sharp. Sol 669 will complete one Martian year.

This map shows in red the route driven by NASA's Curiosity Mars rover from the 'Bradbury Landing' location where it landed in August 2012 to nearly the completion of its first Martian year. The white line shows the planned route ahead.